Brain Aneurysm Surgery: Overview

Repair of a defective artery in the brain

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Brain aneurysm surgery is a major surgical procedure that involves repairing an aneurysm (a defective artery). This surgery may also involve removal of blood from the brain if the aneurysm has ruptured. 

You may have an emergency brain aneurysm operation for management of an acutely bleeding brain aneurysm, or you might have this surgery as a prophylactic planned procedure to prevent a brain aneurysm from rupturing.

brain hemorrhage
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What Is Brain Aneurysm Surgery?

A brain aneurysm is an outpouching in the wall of an artery in the brain. Brain aneurysm surgery is the repair of this arterial defect.

During surgery, the outpouching is usually closed off with a special surgical clip. The portion of the artery that is closed off becomes deprived of blood flow, so the defect will eventually degenerate, and the artery can function as it normally should. 

If the aneurysm has ruptured, leaking and accumulated blood will be removed from the brain during surgery and the artery will be repaired. The repair of a ruptured brain aneurysm can be more complicated than repair of an unruptured brain aneurysm.

Various Surgery Techniques 

There are several ways that brain aneurysm surgery can be performed.


An open craniotomy involves the removal of a small portion of the skull for access to the aneurysm. This procedure would be performed by a neurosurgeon (brain surgeon), and you would have general anesthesia.

Minimally Invasive Surgery

An endovascular repair is a less invasive technique in which a thin surgical catheter (tube) is placed into an artery in the groin and advanced up to the aneurysm in the brain so that it can be repaired. Endovascular repair is done with the assistance of real-time imaging for visualization of the vascular structures.

This procedure would be performed by a neurosurgeon, an interventional neuroradiologist, or an interventional neurologist. It would be done with intravenous (IV, in a vein) sedation and local anesthesia. 

You can have an unruptured aneurysm repaired with an open craniotomy or with an endovascular operation. Sometimes the technique for prophylactically repairing a brain aneurysm is determined based on the location of the aneurysm.

A craniotomy may be necessary for the removal of accumulated blood, and for a complex repair of a ruptured brain aneurysm.


Brain aneurysm surgery can be lifesaving, but it is also high-risk intervention. Some risks can be permanent brain injury and death. If you have brain aneurysm surgery, you will be very closely monitored for complications throughout your recovery.

You and your healthcare provider would weigh the risks and benefits of having your aneurysm prophylactically repaired. For example, you could be at a high risk of life-threatening surgical complications if you have advanced heart disease, end-stage lung disease, or advanced cancer.

While these issues might not necessarily be strict contraindications to surgery, the high risk of having an adverse outcome could be a strong enough reason to consider not having your aneurysm repaired.

If your brain aneurysm has already ruptured and has caused blood to leak into your brain, the effects of the rupture can rapidly worsen. Within hours, a ruptured brain aneurysm can cause severe brain edema (swelling), changes in blood pressure and breathing, and loss of consciousness.

Sometimes these problems can make a person so medically unstable that brain surgery may need to be postponed for hours or days until a person is medically stabilized so that the procedure can be safer. 

Potential Risks 

There are a number of inherent risks with brain surgery and anesthesia. In addition to these risks, brain aneurysm surgery also involves additional risks. 

Potential complications of brain aneurysm surgery include:

  • Damage to the brain 
  • Injury to the aneurysmal artery or other arteries 
  • Bleeding 
  • Infection 
  • Edema (swelling) of the brain 
  • A stroke (an interruption of blood flow in the brain)

The potential outcomes of these issues can include paralysis, behavioral changes, vision loss, speech impairment, seizures, loss of independence, and death

Brain aneurysm surgery complications can occur with a craniotomy or an endovascular procedure. Adverse events can occur with a planned aneurysm repair or with surgery that’s done after an aneurysm has ruptured. These harmful outcomes could occur during your surgery or as you are healing and recovering from surgery.

If you have brain aneurysm surgery, you will be very closely monitored for complications throughout your recovery.

Purpose of Brain Aneurysm Surgery

Brain aneurysm surgery can be done to minimize brain damage if an aneurysm has already bled. And it is done to reduce the risk of brain damage if a non-bleeding brain aneurysm is likely to bleed. 

Often, unruptured brain aneurysms do not cause symptoms. Sometimes, however, they can cause vague effects, such as:

These effects can be constant or intermittent, and they can worsen as the aneurysm enlarges.

A bleeding brain aneurysm may cause a buildup of blood in the brain, which can irritate the brain and produce pressure on the brain. Bleeding and edema could result in severe brain damage. The symptoms of a ruptured brain aneurysm can include:

  • Intense headaches
  • Seizures
  • Paralysis on one side of the body
  • Vision loss
  • Decreased level of consciousness

These effects can begin suddenly and may worsen rapidly, and a ruptured brain aneurysm may even lead to death.

You might not be scheduled for brain aneurysm repair right away after your diagnosis, but your healthcare provider would monitor your aneurysm with regularly scheduled surveillance brain imaging to see if it is getting bigger. And any new or changing neurological symptoms could signal that you are at risk of experiencing a rupture of your brain aneurysm.

It can be difficult to predict with certainty whether a brain aneurysm will rupture. Aneurysms that are large, that are increasing in size, or that have started to leak are more likely to rupture than small brain aneurysms that are not changing in size.

How to Prepare

If your brain aneurysm surgery is planned to prevent the aneurysm from rupturing, you may need to adjust some of your medications the week before your surgery. Your healthcare provider may give you instructions to alter the dose of your blood pressure medication and/or blood thinners.

For a craniotomy, you would need to abstain from food and drink beginning the night before your surgery.

If you are having the operation as an emergency, you will not have time to prepare for surgery on your own ahead of time. You will have intensive medical treatment in the hours before your brain aneurysm surgery while you are in the hospital.

Emergency treatment for a ruptured brain aneurysm can include:

  • Fluid management
  • Medications to reduce brain edema
  • Blood pressure control
  • Support for breathing and supplemental oxygen

Before a prophylactic or emergency brain aneurysm repair, brain imaging tests, such as a computerized tomography (CT) scan, is done so your healthcare provider can visualize the bleeding if you have had any. Your healthcare provider may order an angiogram (an image of the blood vessels) to have a picture of the location, size, and shape of your aneurysm.

What to Expect on the Day of Surgery

When you go for a prophylactic brain aneurysm surgery, you will be coming from home. You'll need to register and sign a consent form when you arrive at your appointment. 

If you are having emergency surgery, you will likely be in the emergency room or intensive care unit (ICU) prior to your operation.

Because of the severe effects of a ruptured brain aneurysm, it is possible that you could be unconscious and unable to consent for surgery. Your family may be asked to consent for you.

For a craniotomy, surgery is performed in a hospital operating room.

  • You will have general anesthesia.
  • Your neurosurgeon will begin your surgery by removing a small portion of your skull.
  • Then your surgeon will access the aneurysm, as well as blood that has leaked.
  • The blood will be removed, and the blood vessel repaired.
  • The small region of the skull that was removed might be replaced.

If you have excessive swelling in the brain, the surgeon may perform a craniectomy. This means that your neurosurgeon will not immediately replace the portion of the skull that was removed for surgery and will do so at a later time when the edema resolves.

This temporary situation is safe, and you will be under medical care in the hospital when your edema is resolving.

If you are having an endovascular procedure, it may be done in an endovascular suite or in a hospital operating room.

  • You will receive a sedative anesthetic medication to make you drowsy.
  • Local anesthetic will be injected in your groin for pain control.
  • A catheter will be placed in your groin and into your femoral artery.
  • With imaging guidance, the catheter will be advanced through arteries in your body and up to your brain aneurysm.
  • The aneurysm will be clipped, typically with a small metal device.
  • Once the aneurysm is clipped, the catheter will be removed, and your sedation will be stopped. 

You will have to stay in the hospital after your brain aneurysm surgery. After a craniotomy, you will go to the intensive care unit (ICU) for post-operative monitoring for several days, and possibly for weeks if you have had a major bleed.

As you improve, you will then be able to go to a regular hospital room and eventually to a rehabilitation facility or to your home.

After an endovascular procedure you may go to an intensive care room or a regular hospital room for several days. If you have an uncomplicated recovery, you will be discharged to go home. 


Recovery after brain aneurysm surgery depends on the extent of damage prior to the surgery. The healing process will be faster and easier, generally taking weeks, after repair of an unruptured brain aneurysm. And it can take months or longer to heal and recover after a brain aneurysm rupture.

After a Prophylactic Surgery

If your surgery was done to prevent an aneurysm rupture, you may need physical therapy. You should not develop substantial new neurological deficits from surgical repair of an unruptured brain aneurysm unless you have had surgical complications.

Any neurological problems that you had prior to your prophylactic surgery (like double vision) may improve after repair of an unruptured brain aneurysm, but your symptoms can persist if brain damage has already occurred.

If you have persistent symptoms, you may need to participate in rehabilitation and/or physical therapy to optimize your recovery after surgery. It is not usually possible to predict whether the symptoms of an unruptured brain aneurysm will improve after the aneurysm is repaired.

The purpose of surgery for an unruptured brain aneurysm is to prevent additional brain damage and to reduce the risk of death.

After an Aneurysm Rupture

Your recovery will take months and will require intensive therapy if you have had brain aneurysm surgery after an aneurysm rupture. You will likely be taking medication to reduce swelling for several weeks. And you might need to return for another surgery to place the portion of your skull that was removed after the edema diminishes if you had a craniectomy.

Long-Term Care

You may have some permanent deficits after your brain aneurysm surgery, especially if your aneurysm ruptured prior to the surgery repair. 


Often, after brain aneurysm surgery, long term care includes periodic surveillance with brain imaging tests to identify any new brain aneurysms that may have developed.

Sometimes, certain hereditary conditions or a history of head trauma can make a person prone to brain aneurysms, and your healthcare provider would monitor you to ensure that any future aneurysms could be identified in time for treatment.

Treatment for Persistent Symptoms

If you had seizures during your hospital stay, you may need to take anticonvulsant medication for the longterm. Sometimes persistent headaches develop after a brain aneurysm rupture, and your healthcare provider may prescribe pain medication for you if you are dealing with persistent head pain.


Therapy can include speech therapy, swallowing therapy, cognitive therapy, physical therapy, and occupational therapy. You and your loved ones may also benefit from counseling, which can help you adjust to the changes that you have to manage after a brain aneurysm rupture.


You may need to make modifications to your daily life. This can include using a walker or a cane to compensate for weakness or diminished balance.

Usually, your healthcare provider will recommend that you try to stay active so you can avoid consequences of decreased mobility, like muscle atrophy and skin sores. This can be challenging, and you should ask for help and guidance if you feel physical discomfort or a lack of motivation.

A Word From Verywell

Brain aneurysm surgery is a type of brain surgery that can be done as a planned procedure or at the time of a ruptured brain aneurysm—which is a serious, life-threatening emergency. The operation can be done with an open craniotomy or as a minimally invasive endovascular surgery.

Recovering from this life-saving operation can take time, and the recovery process will take longer if the aneurysm has already ruptured. If you have had or are considering brain aneurysm surgery, it’s important that you reach out for support before, during, and after your surgery so you can have the best recovery possible for you.

5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Heidi Moawad, MD
Heidi Moawad is a neurologist and expert in the field of brain health and neurological disorders. Dr. Moawad regularly writes and edits health and career content for medical books and publications.